Conventional multi-needle embroidery sewing machines are capable of executing embroidery sewing operations with multiple thread colors. A typical multi-needle embroidery sewing machine of such type is provided with a sewing mechanism and a controller that controls the sewing mechanism. The sewing mechanism is configured, for instance, by a needle-bar case containing six needle bars, a needle-bar selection mechanism, and a needle-bar drive mechanism. The needle-bar selection mechanism selects a given needle by transferring the needle-bar case in the left and right direction and the selected needle bar is connected to the needle-bar drive mechanism to be driven up and down. The sewing mechanism is further configured by a transfer mechanism that transfers an embroidery frame holding a workpiece cloth in the X and Y directions. The controller, on the other hand, receives input of pattern data that contains instructions on the amount of stroke-by-stroke movement of workpiece cloth/embroidery frame, and on timing for changing the thread color, etc. Based on the pattern data, the controller transfers the embroidery frame holding the workpiece cloth in the X and Y directions by the transfer mechanism while controlling other components of the sewing mechanism to form embroidery in multiple colors.
Such multi-needle embroidery sewing machine has found a new application where decorations are created on the workpiece cloth by using a technique called needle punch. To elaborate, needle punches are formed on the workpiece cloth by attaching a needle punch needle on some of the needle bars in place of a sewing needle and driving the needle punch needle based on needle punch information.
Some embroidery sewing machines come with a heat cutter provided with a heater for creating patches of images and characters. Such heat cutters are attached to the carriage of a drive mechanism of an embroidery frame. The heat cutter cuts through fabric and paper to cut out the patches.
The inventors have conceived to utilize the multi-needle embroidery sewing machine as a device for creating patterns on a sheet of workpiece such as paper. One exemplary configuration for creating the patterns with the multi-needle sewing machine may be as follows. Some of the plurality of needle bars is mounted with one or more punch needle(s) for forming penetrations such as small holes instead of a sewing needle(s).
Further, embroidery frame for holding the workpiece being attached to the transfer mechanism may be replaced by a holder providing a secure hold of the workpiece which is also attached to the transfer mechanism. Thus, a desired pattern made of a plurality of penetrations such as small holes can be created on the surface of the workpiece cloth by moving the needle bar(s) having punch needle(s) attached to it up and down by the needle bar drive mechanism while transferring the holder holding the workpiece by the transfer mechanism.
After creating the pattern made of multiplicity of penetrations on workpiece such as paper with the above configured device, the user may desire to cut out the created pattern along the outline of the workpiece. In such case, it would be quite troublesome for the user to neatly cut out the pattern from the workpiece manually with scissors, etc. Thus, the aforementioned cutter may be attached to the sewing machine to cut out the workpiece in the desired shape. Another alternative may be to use a dedicated cutter known as a cutting plotter.
In either of the above alternative cases, a separate cutter or a cutter plotter need to be prepared as an attachment to the sewing machine, and thus, would lead to cost increase of the system. In drawing a pattern on a workpiece sheet based on the punch data through formation of multiplicity of penetrations, it would be further advantageous to prevent ripping of the workpiece sheet which may be caused by interconnection of penetrations that are formed close together. In forming a cut on the workpiece sheet along the outline of the intended pattern, it is desirable to prevent imperfect or premature cut to allow the workpiece sheet to be cut through completely.